<div class="layout">
  <aside>
    <app-side-menu></app-side-menu>
  </aside>

  <header>
    <app-top-bar></app-top-bar>
  </header>

  <main>
    <nz-content>
      <!-- <app-course></app-course> -->
      <router-outlet></router-outlet>
    </nz-content>
  </main>
</div>
